GB2620779A - Electrode materials for li-ion batteries - Google Patents

Electrode materials for li-ion batteries Download PDF

Info

Publication number
GB2620779A
GB2620779A GB2210692.6A GB202210692A GB2620779A GB 2620779 A GB2620779 A GB 2620779A GB 202210692 A GB202210692 A GB 202210692A GB 2620779 A GB2620779 A GB 2620779A
Authority
GB
United Kingdom
Prior art keywords
crystalline material
solid crystalline
cathode
suitably
material according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
GB2210692.6A
Other versions
GB202210692D0 (en
Inventor
Rosseinsky Matthew
Cai Hong
Chen Ruiyong
Daniels Luke
Manning Troy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Liverpool
Original Assignee
University of Liverpool
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Liverpool filed Critical University of Liverpool
Priority to GB2210692.6A priority Critical patent/GB2620779A/en
Publication of GB202210692D0 publication Critical patent/GB202210692D0/en
Priority to PCT/GB2023/051920 priority patent/WO2024018222A1/en
Publication of GB2620779A publication Critical patent/GB2620779A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H01M4/1315—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx containing halogen atoms, e.g. LiCoOxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/56—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO3]2-, e.g. Li2[NixMn1-xO3], Li2[MyNixMn1-x-yO3
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G45/00—Compounds of manganese
    • C01G45/12—Manganates manganites or permanganates
    • C01G45/1221—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof
    • C01G45/1242—Manganates or manganites with a manganese oxidation state of Mn(III), Mn(IV) or mixtures thereof of the type [Mn2O4]-, e.g. LiMn2O4, Li[MxMn2-x]O4
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/54—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [Mn2O4]-, e.g. Li(NixMn2-x)O4, Li(MyNixMn2-x-y)O4
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H01M4/13915—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx containing halogen atoms, e.g. LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/30—Three-dimensional structures
    • C01P2002/32—Three-dimensional structures spinel-type (AB2O4)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/80—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
    • C01P2002/85—Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by XPS, EDX or EDAX data
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/40—Electric properties

Abstract

A solid crystalline material with formula AaMbOyFz, wherein: A is Li, Na, K or Mg; a is 1 to 2; M is one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; b is 1 to 3; and z / (y + z) is 0.20 to 1. The material may be a spinel with space group Fd-3m. The material may have the formula Li1.25Ni0.625Mn1.125O3F. A lithium ion battery may have a cathode comprising the material. The material is intended to have improved long-term cycling performance, capacity and rate performance compared to known cathode materials. The material may be formed by mixing sources of AMO, AF and MF, followed by heating, preferably to a temperature of 300-600 °C. The sources of AMO, AF and MF may be LiNi0.5Mn1.5O4, LiF and NiF2, respectively.

Description

Electrode Materials for Li-ion Batteries
Field
The present invention relates to a solid crystalline material, cathodes comprising the solid crystalline material, lithium-ion batteries and a method of preparing the solid crystalline material. In particular the present invention relates to a solid crystalline material having a spinel crystal structure for use as a cathode active material in a lithium-ion battery.
Background
Lithium-ion batteries (LIBs) have been the subject of much research and development over recent years due to their potential to provide next-generation energy storage devices. LIBs comprise an anode, a non-aqueous electrolyte, a separator and a cathode. In use, the anode and cathode store lithium ions and the electrolyte carries the positively charged lithium ions from the anode to the cathode and vice versa through the separator. During charging, lithium ions are released from the cathode and flow to the anode. During discharging, the lithium ions return to the cathode which generates a flow of electrons through a circuit from the anode to the cathode, powering an attached
device, for example.
The further development of LIBs has been limited by currently available cathode materials. Over decades of development, a wide range of cathode materials have been studied, for example layered oxides LiTMO2 (TM= Ni, Co, Mn), (e.g., NCM811) [1], olivines (e.g., LiFePO4) [2] and spinels (e.g., LiMn204) are typically used as the cathode materials. These cathode materials are advantageous in energy density due to their higher operating voltage or larger discharge capacity than previously developed cathode materials. However, these materials suffer from various problems. For example, capacity decay is a serious problem for spine! LiMn204. Using the beneficial effects of doping this material, LiNi0.5Mni 504 has enhanced structural stability and cycling performance. Spinel LiNiosMni.504 is considered to be a promising high-voltage cathode material for lithium-ion batteries because of its high energy and power density. LiNio5Mni oat has a working potential of 4.7-4.9 V vs Li/Li* and a theoretical capacity of 147 mAh/g. The electrochemical performance of spine! LiNio 5Mni.504 is attributed to a Ni 24/Ni4* redox reaction, with Mn4* remaining unchanged. Therefore the large amount of Mn present in the lattice is not utilized in the electrochemical reactions. The disordered structure of this material with a Fd3m space group exhibits better performance than an ordered spinel structure with a P4332 space group [3].
Spinel-like oxyfluorides Lii.saMni 603.7Fo.3 and Lk saMni 603 4F0 6 were reported to exhibit high energy density and ultrafast rate capability. A discharge capacity of 360 mAh/g was obtained for LitooMni 603.7F0 3 with the contribution of Mn and 0 redox process[4]. These materials have a cation over-stoichiometry composition (the cation to anion ratio is 3.28:4, which is larger than the usual 3:4 in spinel with a general formula of AB2X4, where A and B are cations and X is anion) compared to LiMn204 and exhibit high capacity with the contribution of combined Mn and 0 redox reactions. It was found that the cycling stability was sensitive to the charge cut-off voltage and the materials exhibited fast capacity fade when the charge voltage is over 4.4 V. Since oxygen oxidation often occurs at a relatively high voltage, there is a trade-off between the high capacity and cycling stability.
In addition, the maximum F content in the spinel anionic sublattice, expressed as a fraction of the combined F and 0 content is 0.6/(3.4+0.6) = 0.15.
Transition metal fluorides (e.g., spinel Li2NiF4 and rutile LiMnF4) have been studied as alternative cathode materials due to their high voltages and large theoretical capacities [5, 6]. For example, the theoretical capacity of Li2NiF4 is 360.8 mAh/g. However, Li2NiF4 obtained by calcination shows a discharge capacity of only 118 mAh/g at 0.02 C for voltages of 2.0-4.8V [5]. The limited discharge capacity may be due to its poor electronic conductivity of about 10-7 S/cm.
Considering such known cathode materials, there remains a need for cathode materials with improved performance, such as improved cycle life, rate capability, safety, lower production costs, and lower environmental impact. None of the currently available cathode materials meet all of these requirements.
Summary of the Invention
It is one aim of the present invention, amongst others, to provide a cathode material that addresses at least one disadvantage of the prior art, whether identified here or elsewhere, or to provide an alternative to existing cathode materials. For instance, it may be an aim of the present invention to provide a cathode material which has a high discharge capacity along with favourable cycle life, rate capability and production costs.
According to aspects of the present invention, there is provided a solid crystalline material, a cathode, a lithium-ion battery and a method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and from the description which follows.
According to a first aspect of the present invention, there is provided a solid crystalline material of formula (I): AaMbOyFz, wherein: each A is independently selected from Li, Na, K and Mg; a is from Ito 2; M is selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; b is from 1 to 3; and z / (y + z) is from 0.20 to 1.
As illustrated by the examples presented herein, the inventors have found that the solid crystalline material of this first aspect can perform as a high voltage cathode for use in LIBs. This material has the potential to replace and improve upon currently used cathode materials in LIBs, to provide LIBs with improved performance. These beneficial performance characteristics are believed to be due to the relatively high fluorine content of the material, compared to similar known cathode materials. The requirement that the solid crystalline material has the formula (I) AaMbOyFz, wherein z / (y + 4 is from 0.20 to 1, provides that the material contains at least one fluorine for every four oxygens and may contain more fluorine in relation to oxygen, up to an embodiment wherein the material contains fluorine but no oxygen. Suitably the material comprises at least 20 mol% fluorine in the anionic sublatfice (of the total of oxygen and fluorine content).
Without being bound by theory, the inventors believe that the incorporation of more fluorine compared to oxygen modifies the voltage profile and redox mechanisms involved in the charging/discharging processes to improve the long-term cycling performance, capacity and rate performance of the material compared to similar known materials, such as LiNi0.5Mni 504. This solid crystalline material having the spinel structure may therefore provide a high voltage cathode material for use in LIBs, to improve the performance of said LIBs. The increase in fluorine content compared to known cathode materials is believed to increase the redox voltage of transition metals due to the high electronegafivity of F, whilst allowing for a more Li-rich composition, and therefore providing the performance improvements discussed herein.
The solid crystalline material of this first aspect suitably provides an advantageous active material for a cathode of a lithium-ion battery, which may be particularly useful in applications which require high-speed discharge, such as in power tools.
Preferred features of the solid crystalline material are described below.
Suitably y in formula (I) is from 0 to 4, wherein z / (y + z) is from 0.20 to 1. Suitably z in formula (I) is from 1 to 4, wherein z / (y + z) is from 0.20 to 1. Suitably y is from 0 to 4 and z is from 1 to 4, wherein y and z are selected within these ranges to meet the requirement that z / (y + 4 is from 0.20 to 1.
In some embodiments, z / (y + z) is suitably from 0.20 to 0.67, suitably from 0.20 to 0.5 or from 0.25 to 0.33.
In the solid crystalline material of this first aspect, A is suitably Li. Therefore the material suitably has the formula (lb) LiaMbOyFz. Suitably the material provides a source of lithium ions for use as a cathode active material in a lithium-ion battery.
The metal species M in the solid crystalline material may be selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, and W. The species M may represent a mixture of elements, suitably selected from the list above. In embodiments wherein M is a mixture of elements, b is the relative amount of the combined M species in the formula, and is from Ito 3.
In some embodiments, M comprises Ni and Mn. In such embodiments, M suitably comprises NinMnm, wherein n is from 0 to 3 and m is from 0 to 3. Suitably n is from 0.1 to 1 and m is from 0.5 to 3, suitably wherein n + m is from 1 to 3.
Suitably the ratio of n to m is from 1:1 to 1:3, suitably from 1:1 to 1:2.
In some embodiments, the solid crystalline material contains further M species in addition to the NinMnm discussed above. In such embodiments, the material suitably has a formula (II): AaNinMnniM'bOyFz, wherein: each A is independently selected from Li, Na, K and Mg, preferably Li; a is from 1 to 2; n is from 0 to 3; m is from 0 to 3; M' is selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; b' is from 0 to 1; y is from 0 to 4; z is from 1 to 4; and z / (y + z) is from 020 to 1.
Suitably M' is selected from one or more of Co, V, Cr, Mo, Fe, and W. Suitably b' is from 0.01 to 0.5 or from 0.01 to 0.1.
In some embodiments, the solid crystalline material does not contain any further M species in addition to the NinMnm discussed above. Such embodiments may be advantageous due to the absence of rare and/or expensive metals. Such embodiments may contain only earth abundant metals which may reduce the cost and sustainability of the materials, especially for cobalt-free cathode materials.
Therefore the species M in formula (I) may consist of Ni and Mn. In such embodiments, the solid crystalline material suitably has a formula (llb) AaNinMnmOyFz, wherein: each A is independently selected from Li, Na, K and Mg, preferably Li; a is from 1 to 2; n is from 0 to 3; m is from 0 to 3; y is from 0 to 4; z is from 1 to 4; and z / (y + z) is from 0.20 to 1.
In such embodiments, n + m is suitably from 1 to 3.
In such embodiments, the material suitably has a formula (III): LiaNinMnmOyFz, wherein: a is from 1 to 2; n is from 0.25 to 1; m is from 0.5 to 1.5; y is from 0 to 4.
Suitably y is from 1 to 4.
The solid crystalline material may be considered to be a solid solution of composition between compound (i) LiNi0.5Mni 504 and compound (H) Li2NiF4 (which are end members of the solid solution), wherein the different materials within this range suitably have the same crystal structure. As such, the ratio of compound (i) to compound (ii) within the solid solution may be up to 5:1. Therefore the solid solution may comprise at least 1 equivalent of compound (ii) for every 5 equivalents of compound (i). Suitably the ratio of (i):(ii) within the solid solution is from 51 to 1 to 5, suitably from 5:1 to 1:2 or from 4:1 to 1:1.
Considering the above-described solid solution, the solid crystalline material may have a formula (IV): Lii+xNi1/2+x/2Mn3/2-3x/204-4xF4x; wherein x is from 0.167 to 1, suitably from 0.20 to 1 or from 0.20 to 0.67.
In some embodiments, the solid crystalline material may have formula (IV) wherein x is from 0.25 to 0.33. For example, x may be 0.25 or 0.33 and therefore the solid crystalline material may have formula (V): Lii.251\fi.0 625Mn1 12503F or formula (VI): LiNio.5Mno 7502F.
The solid crystalline material according to this first aspect suitably has a spinel crystal structure, preferably having a Fd3m space group. Suitably this crystal structure is present in each specific material within the range of solid solutions of composition between (i) LiNio5Mm 504 and (ii) Li2NiF4, discussed above. More details of the crystal structure are provided below.
According to a second aspect of the present invention, there is provided a cathode for a lithium-ion battery comprising the solid crystalline material according to the first aspect.
The solid crystalline material may have any of the suitable features or advantages described in relation to the first aspect.
The cathode may comprise at least 75 wt% of the solid crystalline material according to the first aspect, suitably at least 80 wt%, at least 90 wt% or at least 95 wt% of the solid crystalline material. The cathode may comprise a conductive additive and/or a binder. Suitable conductive additives and binders are known in the art. For example, the conductive additive may be a carbon material such as carbon black powder or carbon nanotubes. The binder may be polyvinylidene difluoride (PVDF).
Suitably the cathode consists of the solid crystalline material, the conductive additive and the binder. According to a third aspect of the present invention, there is provided a lithium-ion battery comprising: an electrolyte; an anode; and a cathode comprising a solid crystalline material according to the first aspect.
The solid crystalline material may have any of the suitable features or advantages described in relation to the first aspect.
The cathode is suitably as described in relation to the second aspect.
Suitable anodes and electrolytes for use in the LIB of this third aspect may be as known in the art.
According to a fourth aspect of the present invention, there is provided a method of preparing a solid crystalline material according to the first aspect, the method comprising the steps of: (a) admixing a source of AMO, a source of AF and a source of MF, wherein: each A is independently selected from Li, Na, K and Mg; each M is independently selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; (b) heating the mixture obtained in step (a).
The steps of the method are suitably carried out in the order step (a) followed by step (b).
In the source of AMO, the source of AF and the source of MF, A and M are suitably as described in relation to the first aspect.
Suitably the source of AMO is LiNio5Mni504. Suitably the source of AF is LiF. Suitably the source of MF is NiF2. Suitably each of said reagents is dried before use.
Suitably the method of this fourth aspect is a solid-state reaction wherein each of the sources of AMO, AF and MF are solids.
Suitably step (b) involves heating the mixture obtained in step (a) to a temperature of from 300 to 600°C, suitably from 300 to 500°C suitably wherein the mixture is in a solid state.
Suitably step (b) involves agitation of the mixture and suitably involves applying a force to the mixture.
Suitably step (b) involves grinding or milling the mixture. Suitably step (b) involves ball-milling the mixture.
Suitably the solid crystalline material prepared by the method of this fourth aspect has the formula LiaNinMnmOyF, wherein: a is from Ito 2; n is from 025 to 1; m is from 0.5 to 1.5; y is from 0 to 4; wherein the source of AMO is LiNio.5Mm 504, the source of AF is LiF and the source of MF is NiF2.
Suitably y is from Ito 4.
According to a further aspect of the present invention, there is provided a use of a solid crystalline material according to the first aspect as a cathode material in a lithium-ion battery. The suitable features and advantages of this use and the material are as described in relation to the first, second and third aspects of the invention above and also in the description of the examples which follows.
Brief Description Of The Figures
The following examples refer to the accompanying figures in which: Figure 1 shows the Pawley fitting of the diffraction pattern with a cubic spine! phase (Fdrn space group, a = 8.2242(25) A).
Figure 2 shows a) high-resolution transmission electron microscopy image of LNMOF (inset: the FFT pattern), b) STEM-HAADF image and the selected area for EELS analysis, and c) EELS spectra of the 0 K edge, Mn L edge, F K edge and Ni L edge.
Figure 3 shows: a) galvanostatic charge and discharge performance for an 8th cycle of sample tested at different cut-off voltages b) discharge capacity retention rate over time c) the charge and discharge performance of the sample at different current rates, and d) rate performance at different current rates for a 2-5 V voltage window at room temperature.
Figure 4 shows a) a cycling stability comparison between LiNio5Mni.504 (referred to herein as LNMO) and LNMOF over 1.5 -5 Vat 10 mA g-1, b) rate performance between 1.5-4.8 Vat 40°C (10 mA/g to 100 mA/g).
Figure 5 shows: a) Ex situ XRD patterns of Lii 25Nio a25Mni 12503F sample at different stages of charge (5 and 5.3 V) and discharge (2 and 1.5 V), b) Pawley fitting of the fully charged sample at 5.3 V and c) change of lattice parameters (a and 1/) at different charge and discharge voltages.
Examples
The following describes the preparation of Li1.25Nio.625Mn1 12503F (a solid solution between LiNio sMni.504 and Li2NiF4) with the aim of raising the voltage of operation and cycling performance of the material compared to commercially available cathode materials. The electrochemical performance of the phase pure Lk 25Ni0525Mm.12,503F (referred to herein as LNMOF) was tested and the results are described below.
Preparation of Li, 25Ni0 525A4n1 1250 F The solid crystalline material Li, 25Ni0.625Mni.12503F (referred to herein as LNMOF) was prepared according to the following procedure. The Lii 25Nio 625Mni 12503F corresponds to the AaMbOyFz, where A = Li, a = 1.25, M = Ni, Mn, b= 1.75, y = 3, z =1, z/(y+z)=0.25. The precursors for Lii.25Nio 625Mni.12503F (0/F=3), LiNio 5Mni 504 (>99%, Sigma Aldrich), LiF (>99.99%, Alfa Aesar), and NiF2 (Sigma Aldrich) were all dried before use. Different drying procedures were used to ultra-dry the starting materials. LiF was dried under Ar at 400°C for 6 h. NiF2 was dried under Ar at 450°C for 12 h. LiNio5Mni.504 was dried overnight at 200°C in air. After drying, all the starting materials were handled inside an argon-filled glovebox. The synthesis route used stoichiometric amounts of LiNio5Mni 504, LiF and N1F2 as starting material. Stoichiometric amounts of LiNio sMni.s04 (794.7 mg), LiF (74.5 mg) and N iF2 (138.8 mg) were mixed with a total mass of 1 g. The precursor mixture was then transferred into a 45 ml zirconia jar with zirconia balls (20 g in total) of 5 mm in diameter. The milling jar was then sealed in an Ar-filled glovebox. After high-energy ball milling at 450 rpm for 20 h under Ar atmosphere, the ball-milled powders of 50 mg were pressed into a pellet with a diameter of 10 mm at 2 tons. The pellets were then transferred into a Ni foil wrapped alumina crucible. The crucible was placed in a quartz tube which can be sealed both sides using tube end caps with tap and then heated at 400°C for 30 min under Ar flow. This resulted in the target material 25Ni0.625Mm 12503F as a powder.
Characterisation of Lb 2.5Nio 625Mni 1250 F The LNMOF prepared as described above was analysed by powder X-ray diffraction and elemental analysis. The morphology of the particles was observed using a scanning electron microscope and a transmission electron microscope.
Regarding the elemental analysis, Table 1 below shows the target vs. measured atomic ratio of the LNMOF sample by combining inductively coupled plasma (ICP) and wavelength-dispersive X-ray spectroscopy (VVDX).
To quantify cation contents of the samples by ICP, 20 mg of each powder were dissolved in concentrated HCI and diluted to 100 ml. Quantitative elemental analysis of the as-synthesised Lii.25Ni0625Mnti2503F was performed by combined ICP and WDX (Table 1). F content was further quantified via F-ion selective electrode (F-ISE, Table 1).
Table 1
Lii 25Ni0.625Mni 12503F Target As-synthesized Li/Mn (ICP) 1.11 1.12 Ni/Mn (VVDX) 0.555 0.541 0c011/Mn (VVDX)* 2.667 2.621 Fc0SMn (VVDX)4 0.888 0.774 F (F-ISE) 1 0.97 *0 was corrected using LiNio5Mni 504 F was corrected by BiOF The elemental analysis discussed above derived from VVDX measurement and ICP corroborate the expected composition for this sample.
Crystal structure of Li1.25Ni0.525Mn1.12503F Powder X-ray diffraction with Mo Ka radiation (on a Rigaku Mo diffractometer, A = 0.70930 A) was used to identify the crystalline phase.
Figure 1 shows the Pawley fitting of the diffraction pattern with a cubic spine! phase (Fclm space group, a = 8.2242(25) A).
The X-ray diffraction pattern can be well indexed in a spine! phase (Fd3m space group), with no peaks referring to impurities. The lattice constant of the sample was also obtained from the Pawley fitting, which is 8.2242(25) A. The value is in the range between lattice constant of LiNio.5Mni504 and Li2NiF4, which are 8.178 A and 8.318 A, respectively. The result further confirms the formation of solid solution between these two end compounds.
Figure 2 shows a) high-resolution transmission electron microscopy image of LNMOF (inset: the FFT pattern), b) STEM-HAADF image and the selected area for EELS analysis, and c) EELS spectra of the 0 K edge, Mn L edge, F K edge and Ni L edge.
Figure 2a shows the atomic resolution high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) image of a Lii 25Nio ezsMni 12503F particle. It shows the high crystallinity of the primary particle. The corresponding fast Fourier transform (FFT) analysis (inset in Figure 2a) confirms the spinel structure of Lii.25Nio625Mm 12503F particle at atomic scale. Using electron energy loss spectroscopy (EELS) in the area marked in Figure 2b, the presence of 0, Mn, F and Ni in a primary particle can be confirmed (Figure 2c).
Electrochemical performance of Lir 25Ni0 625Mh1 12503F cathode The electrochemical performance of the solid crystalline material LNMOF was tested by forming a cathode from the material and setting up and testing an experimental cell. The powder LNMOF material was mixed with carbon black (25 wt%) and PVDF (10 wt%) in n-methyl pyrrolidinone and hand-ground for 30 min. Then it was painted onto a stainless-steel disk and dried overnight in an Ar-filled glovebox to provide the cathode. This cathode was combined with a lithium foil as an anode and an electrolyte of 1M LiPF5 in ethylene carbonate (EC) and dimethyl carbonate (DMC) (1:1, v/v) electrolyte to form the experimental cell.
Figure 3 shows: a) galvanostatic charge and discharge performance for an 8th cycle of sample tested at different cut-off voltages b) discharge capacity retention rate over time c) the charge and discharge performance of the sample at different current rates, and d) rate performance at different current rates for a 2-5 V voltage window at room temperature.
Figure 3 shows the electrochemical properties of LNMOF cathode material against a Li anode at room temperature using 1M LiPF6 in EC/DMC (1:1 vol.°/0). After a few initial cycles, the charge/discharge voltage profiles reached a steady state. Figure 3 a) shows the discharge and charge profiles at 8111 cycles measured at 10 mA g-1 and different cut off voltage ranges. High discharge capacity was observed at a broader voltage window between 1.5 and 5 V. The observed reversible discharge capacity of 219 mAh g-1 corresponds to -1.4 Li* capacity. This means additional Li has been intercalated into this spinel lattice when the discharge cut-off voltage allows an Me* reduction reaction. When the discharge cut-off voltage was set to 2, 2.5 and 3 V, the discharge capacity reduced to 175, 150 and 100 mAh g-1, respectively. The discharge voltage bump at about 4.5 V became clearer when the charge cut-off voltage was set to 5.3 V. Good capacity retention was observed independent of the cut-off voltages. This is distinct compared to the previous reported spinel-like material Li, 58Mni.604-.F. (x= 0.3; 0.6), which shows fast capacity fading when charge cutoff voltage is over 4.4 V [4].
Figure 3b shows the corresponding cycling stability of Li, 25Ni.0 625Mn1 12503F tested at 10 mA g-1 and different cut-off voltages. The discharge capacity decreases from 225 mAh g-' from the third cycle to about 200 mAh g-1 after 40 cycles, corresponding to a 0.28% capacity loss per cycle. A relatively fast capacity fading (about 1.1% capacity loss per cycle) was observed when tested with a high charge cut-off voltage of 5.3 V. Accordingly, the decomposition of the electrolyte becomes obvious at such a high voltage with a low coulombic efficiency. Coulombic efficiencies of all other cells tested at different voltage ranges reached about 95% after a few cycles. All other cells showed good capacity retention over cycling, independent of the cut-off voltages. Between 3 and 5 V, the capacity loss per cycle was 0.18% over 160 cycles. This is distinct from the previous reported spinel-like Li1.68Mni 504_.F. cathodes (x = 0.3; 0.6) [4] which showed fast capacity fading (about 4.1% and 2.3% capacity loss per cycle for x = 0.3 and x = 0.6, respectively, measured at 50 mA g-1 and room temperature) with a charge cut-off voltage of 4.8 V. This good capacity retention observed for Lii.25Nio.625Mni 12503F material indicates that this material has good structural tolerance to deep delithiation.
Rate performance of Li, 25Nio e25Mni 12503F was tested at room temperature between 2 and 5 V from 10 to 100 mA gland the results are shown in Figure Sc. Preparation of coin cells forthe rate capability measurements involved mixing 65 wt% of active material, 10% wt of PVDF and 25 wt% of carbon black together. The results show that from 10 to 20, 50 and 100 mA g-1, the capacity reduces slightly from 195 to 180, 170 and 158 mAh g-1, respectively. Figure 3d shows the capacity retention of the cell tested at different current densities. Five cycles were measured at each current step, and then the cells were subjected to a second round from low to high current densities. The Li1.25Nio625Mn1.12503F material shows good capacity retention over 40 cycles.
Figure 4 shows a) a cycling stability comparison between LiNiosMni 504 (referred to herein as LNMO) and LNMOF over 1.5 -5 V at 10 mA g-1, b) rate performance between 1.5-4.8 V at 40°C (10 mA/g to 100 mA/g).
The Lir.25Nioz25Mni.i25OsF showed better capacity retention compared to the commercially available LiNio sMni.504 material when tested at the same voltage range (Figure 4a). In addition, the rate performance was evaluated at 40°C between 1.5 and 4.8 V (Figure 4b). Compared to the room temperature results, higher discharge capacity of 285 (i.e., 1.82 Li + capacity), 225, 210 and 195 mAh g-1 was observed at 10, 20, 50 and 100 mA g-1, respectively. A comparable capacity of mAh g-1 (roughly the theoretical capacity of the Li1.25Ni0625Mn, 12503F) was observed at 100 mA g-1 at 40 °C, similar to that tested at room temperature at 10 mA g-1. A high capacity of about 150 and 120 mAh g-1 was still observed at 200 and 400 mA g-1 at 40°C, respectively.
Figure 5 shows: a) Ex situ XRD patterns of Li1.25Nio.625Mni 12503F sample at different stages of charge (5 and 5.3 V) and discharge (2 and 1.5 V), b) Pawley fitting of the fully charged sample at 5.3 V and c) change of lattice parameters (a and 1/) at different charge and discharge voltages.
Samples at different states of charge (5 and 5.3 V) and discharge (2 and 1.5 V) were collected for ex situ structural analysis (Figure 5a-5c). The spinel phase remains at all states of charge/discharge with only slight shifts in the diffraction peaks (Figure 5a), suggesting a reversible single-phase (de)lithiafion reaction. Such structural integrity is likely responsible for the observed good cycling stability. The lattice parameter decreases during charge from 8.224(3) A at open circuit voltage (OCV) to 8.2117(26) A at 5.3 V (Figure 5b), and then increases to 8.299(5) A after discharging to 1.5 V (Figure Sc). This corresponds to a lattice volume contraction of 1.84 % after charge to 5.3 V, and a lattice volume expansion of 1.16 % after discharge to 1.5 V. In summary, the present invention provides a solid crystalline material with relatively high fluorine incorporation which shows beneficial electrochemical properties and may be formed of earth abundant elements. The solid crystalline material of formula (I) may therefore provide an advantageous active material for a cathode of a lithium-ion battery.
References [1] G. Zha, W. Hu, S. Agarwal, C. Ouyang, N. Hu, and H. Hou, "High performance layered LiNio8C0007Feo 03Mno.102 cathode materials for Li-ion battery," Chemical Engineering Journal, vol. 409, p. 128343, 2021/04/01/2021.
[2] S. Sun et al., "Changes of Degradation Mechanisms of LiFePO4/Graphite Batteries Cycled at Different Ambient Temperatures," Electrochimica Acta, vol. 237, pp. 248-258, 2017.
[3] J. H. Kim, S. T. Myung, C. S. Yoon, S. G. Kang, and Y. K. Sun, "Comparative Study of LiNio 5Mni.504-6 and LiNio5Mn1 504 Cathodes Having Two Crystallographic Structures: Fd3m and P4332," Chemistry of Materials, vol. 16, no. 5, pp. 906-914, 2004/03/01 2004.
[4] H. Ji et aL, "Ultrahigh power and energy density in partially ordered lithium-ion cathode materials," Nature Energy, vol. 5, no. 3, pp. 213-221, 2020/03/01 2020.
[5] N. Kimura, H. Nasu, Y. Kohno, and Y. Tomita, "Synthesis and charge-discharge properties of 2LiF-NiF2 composite and Li2NiF4 as a cathode material for Li-ion batteries," Transactions of the Materials Research Society of Japan, vol. 45, no. 1, pp. 15-18, 2020.
[6] N. Twu, X. Li, C. Moore, and G. Ceder, "Synthesis and Lithiafion Mechanisms of Dirutile and Rutile LiMnF4: Two New Conversion Cathode Materials," Journal of The Electrochemical Society, vol. 160, no. 11, pp. Al 944-A1951, 2013.
Although a few preferred embodiments have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims.
Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of other components. The term "consisting essentially of' or "consists essentially of' means including the components specified but excluding other components except for materials present as impurities, unavoidable materials present as a result of processes used to provide the components, and components added for a purpose other than achieving the technical effect of the invention. Typically, when referring to compositions, a composition consisting essentially of a set of components will comprise less than 5% by weight, typically less than 3% by weight, more typically less than 1% by weight of non-specified components.
The term "consisting of' or "consists or means including the components specified but excluding addition of other components.
Whenever appropriate, depending upon the context, the use of the term "comprises" or "comprising" may also be taken to encompass or include the meaning "consists essentially of' or "consisting essentially of', and may also be taken to include the meaning "consists of' or "consisting of'.
For the avoidance of doubt, wherein amounts of components in a composition are described in wt%, this means the weight percentage of the specified component in relation to the whole composition referred to.
The optional features set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional features for each aspect or exemplary embodiment of the invention as set out herein are also to be read as applicable to any other aspect or exemplary embodiments of the invention, where appropriate. In other words, the skilled person reading this specification should consider the optional features for each exemplary embodiment of the invention as interchangeable and combinable between different exemplary embodiments.
Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All of the features disclosed in this specification (including any accompanying claims, and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims (17)

  1. Claims 1. A solid crystalline material of formula (I): AaMbOyFz, wherein: each A is independently selected from Li, Na, K and Mg; a is from 1 to 2; M is selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; b is from 1 to 3; and 71 (y + z) is from 0.20 to 1.
  2. 2. The solid crystalline material according to claim 1, wherein A is Li.
  3. 3. The solid crystalline material according to claim 1 or claim 2, wherein the material has a spinel crystal structure, preferably having a Fd3m space group.
  4. 4. The solid crystalline material according to claim 1 or claim 2, wherein M is selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, and W, preferably wherein M comprises Ni and Mn.
  5. 5. The solid crystalline material according to claim 4, wherein M comprises NinMrim and n is from 0 to 3 and m is from 0 to 3.
  6. 6. The solid crystalline material according to claim 5, wherein n is from 01 to 1 and m is from 0.5 to
  7. 7. The solid crystalline material according to any one of the preceding claims, wherein y is from 0 to
  8. 8. The solid crystalline material according to any one of the preceding claims, wherein z is from 1 to 4
  9. 9. The solid crystalline material according to any one of the preceding claims, having a formula (II): AaNinMnmM'bOyFz, wherein: each A is independently selected from Li, Na, K and Mg; a is from 1 to 2; n is from 0 to 3; m is from 0 to 3; M' is selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; b' is from 0 to 1; y is from 0 to 4; and z is from 1 to 4.
  10. 10. The solid crystalline material according to any one of the preceding claims, having a formula (Ill): LiaNinMnmOyF, wherein: a is from 1 to 2; n is from 0.25 to 1; m is from 0.5 to 1.5; y is from 0 to 4.
  11. 11. The solid crystalline material according to any one of the preceding claims, having a formula (IV): Lil+xN /2+x/2M n3/2-3x/204-4xF4x, wherein x is from 0.25 to 1.
  12. 12. The solid crystalline material according to any one of the preceding claims, having formula (V): Li1.25Ni0625Mn1.12503F or formula (VI): LiNi0.5Mno7502F.
  13. 13. A cathode for a lithium-ion battery comprising the solid crystalline material according to any preceding claim.
  14. 14. A lithium-ion battery comprising: an electrolyte; an anode; and a cathode comprising a solid crystalline material according to any of claims 1 to 12.
  15. 15. A method of preparing a solid crystalline material according to any of claims 1 to 12, the method comprising the steps of (a) admixing a source of AMO, a source of AF and a source of MF, wherein: each A is independently selected from Li, Na, K and Mg; each M is independently selected from one or more of Ni, Mn, Co, V, Cr, Mo, Fe, W, Y, Si, Ti, Zr, Nb, Ta, Ag, Cu, Zn, Sn, Mg, Al; (b) heating the mixture obtained in step (a).
  16. 16. The method according to claim 15, wherein step (b) involves heating the mixture obtained in step (a) to a temperature of from 300 to 600°C.
  17. 17. The method according to claim 15 or claim 16, wherein the solid crystalline material has the formula (Ill): LiaNinMnmOyF, wherein: a is from 1 to 2; n is from 0.25 to 1; m is from 0.5 to 1.5; y is from 0 to 4; wherein the source of AMO is LiNi0.5Mni 504, the source of AF is LiF and the source of MF is NiF2.
GB2210692.6A 2022-07-21 2022-07-21 Electrode materials for li-ion batteries Pending GB2620779A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB2210692.6A GB2620779A (en) 2022-07-21 2022-07-21 Electrode materials for li-ion batteries
PCT/GB2023/051920 WO2024018222A1 (en) 2022-07-21 2023-07-20 Electrode materials for li-ion batteries

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2210692.6A GB2620779A (en) 2022-07-21 2022-07-21 Electrode materials for li-ion batteries

Publications (2)

Publication Number Publication Date
GB202210692D0 GB202210692D0 (en) 2022-09-07
GB2620779A true GB2620779A (en) 2024-01-24

Family

ID=84540504

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2210692.6A Pending GB2620779A (en) 2022-07-21 2022-07-21 Electrode materials for li-ion batteries

Country Status (2)

Country Link
GB (1) GB2620779A (en)
WO (1) WO2024018222A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040185345A1 (en) * 2002-03-08 2004-09-23 Daisuke Kawasaki Positive electrode active material for secondary cell, positive electrode for secondary cell using same, and secondary cell
US20110017946A1 (en) * 2009-07-27 2011-01-27 Samsung Electronics Co., Ltd. Cathode active material, cathode including cathode active material, and lithium battery including cathode
US20160028074A1 (en) * 2014-07-22 2016-01-28 Toyota Jidosha Kabushiki Kaisha Positive electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery
US20180069267A1 (en) * 2015-09-16 2018-03-08 Panasonic Intellectual Property Management Co., Ltd. Battery
US20180090747A1 (en) * 2015-07-23 2018-03-29 Panasonic Intellectual Property Management Co., Ltd. Positive-electrode active material and battery
US20180205073A1 (en) * 2017-01-19 2018-07-19 Panasonic Intellectual Property Management Co., Ltd. Positive electrode active material containing lithium composite oxide and lithium composite oxyfluoride, and battery including positive electrode containing positive electrode active material

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040185345A1 (en) * 2002-03-08 2004-09-23 Daisuke Kawasaki Positive electrode active material for secondary cell, positive electrode for secondary cell using same, and secondary cell
US20110017946A1 (en) * 2009-07-27 2011-01-27 Samsung Electronics Co., Ltd. Cathode active material, cathode including cathode active material, and lithium battery including cathode
US20160028074A1 (en) * 2014-07-22 2016-01-28 Toyota Jidosha Kabushiki Kaisha Positive electrode active material for lithium secondary battery, positive electrode for lithium secondary battery, and lithium secondary battery
US20180090747A1 (en) * 2015-07-23 2018-03-29 Panasonic Intellectual Property Management Co., Ltd. Positive-electrode active material and battery
US20180069267A1 (en) * 2015-09-16 2018-03-08 Panasonic Intellectual Property Management Co., Ltd. Battery
US20180205073A1 (en) * 2017-01-19 2018-07-19 Panasonic Intellectual Property Management Co., Ltd. Positive electrode active material containing lithium composite oxide and lithium composite oxyfluoride, and battery including positive electrode containing positive electrode active material

Also Published As

Publication number Publication date
WO2024018222A1 (en) 2024-01-25
GB202210692D0 (en) 2022-09-07

Similar Documents

Publication Publication Date Title
Xu et al. Progressive concentration gradient nickel-rich oxide cathode material for high-energy and long-life lithium-ion batteries
Zheng et al. Exploring the working mechanism of Li+ in O3-type NaLi 0.1 Ni 0.35 Mn 0.55 O 2 cathode materials for rechargeable Na-ion batteries
Chen et al. Stable layered P3/P2 Na 0.66 Co 0.5 Mn 0.5 O 2 cathode materials for sodium-ion batteries
Liu et al. General synthesis of x Li 2 MnO 3·(1− x) LiMn 1/3 Ni 1/3 Co 1/3 O 2 nanomaterials by a molten-salt method: towards a high capacity and high power cathode for rechargeable lithium batteries
Knight et al. Effect of Ru substitution on the first charge–discharge cycle of lithium-rich layered oxides
Li et al. General synthesis of x Li 2 MnO 3·(1− x) LiNi 1/3 Co 1/3 Mn 1/3 O 2 (x= 1/4, 1/3, and 1/2) hollow microspheres towards enhancing the performance of rechargeable lithium ion batteries
KR20150073969A (en) Li-Ni COMPOSITE OXIDE PARTICLE POWDER AND METHOD FOR MANUFACTURING SAME, AND NONAQUEOUS ELECTROLYTE SECONDARY CELL
EP3085669B1 (en) Lithium complex oxide
Shen et al. Spray pyrolysis and electrochemical performance of Na0. 44MnO2 for sodium-ion battery cathodes
Verrelli et al. A lithium ion battery exploiting a composite Fe 2 O 3 anode and a high voltage Li 1.35 Ni 0.48 Fe 0.1 Mn 1.72 O 4 cathode
Ahn et al. Achieving high capacity and rate capability in layered lithium transition metal oxide cathodes for lithium-ion batteries
Boddu et al. Hysteresis abated P2-type NaCoO 2 cathode reveals highly reversible multiple phase transitions for high-rate sodium-ion batteries
Kim et al. Improving LiNiO 2 cathode performance through particle design and optimization
Cao et al. Oxygen redox chemistry in P2-Na 0.6 Li 0.11 Fe 0.27 Mn 0.62 O 2 cathode for high-energy Na-ion batteries
Baboo et al. Facile redox synthesis of layered LiNi1/3Co1/3Mn1/3O2 for rechargeable Li-ion batteries
Han et al. The effects of copper and titanium co-substitution on LiNi 0.6 Co 0.15 Mn 0.25 O 2 for lithium ion batteries
Li et al. Role of Hydrothermal parameters on phase purity of orthorhombic LiMnO2 for use as cathode in Li ion battery
Zan et al. Layered-tunnel structured cathode for high performance sodium-ion batteries
JP6536939B2 (en) Positive electrode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using the same
Liu et al. Predominant growth orientation of Li 1.2 (Mn 0.4 Co 0.4) O 2 cathode materials produced by the NaOH compound molten salt method and their enhanced electrochemical performance
Satyanarayana et al. Electrochemical performance of LiNi0. 4Co0. 2Mn0. 4O2 prepared by different molten salt flux: LiNO3-LiCl and LiNO3-KNO3
Mezaal et al. Promoting the cyclic and rate performance of lithium-rich ternary materials via surface modification and lattice expansion
WO2022182313A2 (en) Development of new air-stable o3-naxmo2 type layered metal oxides for sodium ion batteries
Deng et al. The enhancement of rate and cycle performance of LiMn 2 O 4 at elevated temperatures by the synergistic roles of porous structure and dual-cation doping
GB2620779A (en) Electrode materials for li-ion batteries